1. Field of Invention
The invention relates generally to computer systems, and deals more particularly with a technique to monitor an amount of usage of applications in logical partitions for billing or other purposes.
2. Description of Related Art
Computer systems are well known today, and comprise hardware and software components such as one or more processors, memory, storage, I/O devices to access storage, one or more operating systems and applications. Some types of computer systems are logically partitioned by a central operating system into separate, “logical” computers. A logical partition (“LPAR”) can be the basis for a virtual machine or non virtual machine environment. Each logical partition comprises a share of the computer resources, and executes a guest operating system and application(s) using that share of the computer resources. For example, each logical partition may be given a periodic, time slice of the system's processor(s) to execute the operating system and application(s) within the logical partition. So, if a computer system is logically partitioned into ten logical computers, and each partition has an equal share of computer resources, then each logical partition can be executed on the processor(s) ten milliseconds every hundred milliseconds. In this manner, the applications within each logical partition execute as if they have their own dedicated computer resources (although the applications may be dormant ninety percent of the time). Alternately, if there are multiple processors in the system, each logical partition can have some of the processors dedicated to it.
The “share” of system resources for each logical partition is generally specified by a systems administrator during or before Initial Micro code Load (“IML”) (but, in some cases, can be changed dynamically without IML), and this is based on an estimate of the relative needs of all the logical partitions for the finite computer resources. However, the specified share of computer resources for a logical partition may be greater (or lesser) at times than actually needed. For example, assuming the application(s) in the logical partition handle user requests, the frequency of the user requests may vary from time to time. During times of fewer requests, the applications in the logical partition may not need the entire share of hardware resources allocated to it. So, the logical partition may begin to execute during its allocated time slice, but complete its outstanding requests before the end of the time slice. In such a case, the operating system in the logical partition will notify the central operating system to suspend its execution for the remainder of the time slice. Then, the next logical partition in the sequence will immediately begin its time slice (earlier than scheduled), as will the subsequent logical partitions in the sequence. If the other logical partitions use their entire allocated time slice, then the actual share of processor time used by the one logical partition with the fewer user requests will be less than the specified share. In the case where the logical partition has more requests than can be handled in the specified share of processor time, there is not ordinarily any automatic upgrade to the allocated share of computer resources. Instead, the users and/or systems administrator may notice a slow operation for the applications in the logical partition, and the systems administrator can then adjust the specified share for the logical partition, reconfigure the logical partitions or take other action.
There are different reasons for logical partitioning. One reason is to isolate the applications in one logical partition from the applications in the other logical partitions. For example, different users can have their applications run in different logical partitions for improved reliability, security, availability, maintainability, etc. Another reason is for billing purposes. Today customers purchase computer systems with greater capacity than is required. This is done in anticipation of future peak computing demands. Customers initially register and enable some but not all of their system's Central Processors (CPs). They are then billed based on the number of CPs that are enabled, i.e. the enabled computing capacity. When customers need additional computing power (at least on a peak basis), they may register and pay for more CPs.
It was known for the computer hardware and system operating system to track and record in a system log which LPAR is currently executing and on which processor(s). The LPAR usage information was subsequently used to compute the amount of processor usage by each logical partition per hour, and therefore, whether each LPAR has the proper processor capacity. The LPAR usage information and computation of processor usage were also sent to a systems administrator.
It was also known for a guest operating system in each LPAR to track when each application begins execution and ceases execution, as “binary application indicator” information. (It was also known for another guest operating system to measure the time that each application is dispatched.) The “binary application indicator” information indicates whether the respective application ran at any time during the previous sampling period. The guest operating system recorded this binary application indicator information in storage private to the LPAR. It was also known for the guest operating system in each LPAR to track overall resource consumption in a sampling period, i.e. the amount of service unites consumed by all program functions (i.e. guest operating system, applications, etc.) in the LPAR during the sampling period. The guest operating system recorded this resource consumption information in storage private to the LPAR. A prior art software-based reporting system cross-referenced/compiled the application indicator information for the respective LPAR and the corresponding LPAR resource consumption information. This cross referencing/compiling produces a report which indicates how many service units were used by all the LPARs that executed each application during the previous sampling period. If two applications ran in an LPAR, then each application was charged for the overall resource consumption of the entire LPAR. This report was then used to determine an amount to charge the customer for the usage of each application. Customers then manually submit the cross referencing reports to the owner of the applications. These reports are input to an auditing and pricing application in a remote work station of the owner. While the foregoing process for a software-based reporting system was effective, it required that (a) the guest operating system in each LPAR track when each application begins and ceases execution, (b) the guest operating system in each LPAR track overall resource consumption of the LPAR and (c) the software-based reporting system cross reference data from each LPAR. This was burdensome to the systems administrator because there can be many LPARs in each system. Also, some reports are susceptible to customer tampering.
An object of the present invention is to provide a less burdensome technique to monitor and report usage of individual applications in an LPAR.
Another object of the present invention is to provide a technique to confirm the foregoing usage report for auditing or other purposes.